[(1S,2R)-3-[[(4-aminophenyl)sulfonyl](2-methylpropyl)amino]-2-hydroxy-1-(phenyl methyl)propyl]-carbamic acid (3R,3aS,6aR)hexahydrofuro[2,3-b]furan-3-yl ester is commonly known as Darunavir. The Darunavir is a protease inhibitor drug used to treat HIV infection. Prezista is an OARAC recommended treatment option for treatment-naïve and treatment-experienced adults and adolescents.
Darunavir was first generically disclosed in U.S. Pat. No. 5,843,946 and specifically disclosed in U.S. Pat. No. 6,248,775.
U.S. Pat. No. 7,126,015 discloses process for the preparation of (3R,3aS,6aR)-hexahydrofuro[2,3-b]furan-3-ol. The disclosed process involves cyclisation of (R)-3-((R)-2,2-dimethyl-1,3-dioxolan-4-yl)-4-nitrobutan-1-ol in presence of potassium tert-butoxide in isopropanol followed by reaction with concentrated hydrochloric acid to give mixture of compound of formula-2 i,e. (3R,3aS,6aR)-hexahydrofuro[2,3-b]furan-3-ol in a ratio of 78:22 which results in the formation of final product with low yield and low purity. Further the final compound of formula-2 was purified by column chromatography, which is a laborious and time consuming process and also it is not suitable for commercial scale purpose.
Hence, there is a need in the art to develop an improved, economical viable and efficient, simple process for the preparation of (3R,3aS,6aR)-hexahydrofuro[2,3-b]furan-3-ol compound of formula-2 with high yield and purity.